This digital clock is perfect for playing chess and other games that require countdown, counting, bonuses and delays. It is lightweight and compact in size, so it fits comfortably in most bags and can be taken with you to club or tournament events. Functions: Basic: Set the base time. Bonus: Set the basic time and bonus time. Delay: Set the basic time, second reading time, and time. Large flexible button with better sense of press. High quality of ABS plastic durable material shell. Available for bonus &? delay mode. Portable energy saving design. This digital clock is perfect for chess and other games that require countdown, count up, bonus, and delay times. It's lightweight and small in size, so it fits in most bags conveniently and is portable to take to and from club or tournament events. Functions: Basic : Set basic time. Bonus：Set basic time and bonus time. Delay：Set basic time, second reading times and time. Positive Timing: Set basic time to be 0 for overall rationing system Specifications: Material: ABS Color: Black/Yellow (Optional) Battery: 2 * AAA battery (included) Screen size: 103 * 23mm / 4.06 * 0.91in Item size: 140 * 88 * 45mm / 5.51 * 3.46 * 1.77in Item weight: 105g / 3.70ounce Package size: 150 * 100 * 50mm / 5.91 * 3.94 * 1.97in Package weight: 157g / 5.54ounce Packing List: 1 * Chess Clock